This is so interesting that you mentione that. I also remember the EXACT date this started. It was February 17 2011. I ALSO started putting ground chia seed in my oatmeal a week or so prior!! Chris seed is very high in fiber and expands in your stomach .. To make you feel full. When the sensation of not being able to take a deep breath/trying to yawn started I thought maybe its the chia seed but dismissed it. I just started using it again along with hemp seed and flax seed and my breathing is noticeably worse!!

I hope it turns out to be the case, i am convinced it is more to do with my stomach and the bloating then my throat. It definatley sounds like you also have a reaction to the high fiber in your diet. I wonder how many more sufferers are possibly having an intolerance to the fiber in their diets.

Good luck and i hope it turns out to be chia seeds for you as at least knowing what is causing your symptoms means that we can hopefully find a solution.